Lightning-arrester.



E. BENNETT.

LIGHTNING ARR-ESTER.

APPLIOATION FILED AUG. 26, 1908. RENEWED FEB. 6, 1914 1,1 10,179.Patented Sept. 8, 1914 3 SHEETSSHEET 1.

I B. BENNETT. MGHTNING ARRBSTER. APPLIUATIOI? FILED AUG. 26, 190B.RENEWED FER- 6, 1914.

1 1 lg l'yg Patented Sept. 8,1914

3 SHEETS*SHEET 2.

E. BENNETT.

LIGHTNING AERESTER.

APPLICATION FILED we. 26, 1908. RENEWED 1 313.6, 1914.

1,1 10,179. Patented Sept. 8, 1914.

3 SHEETS-SHEET 3.

l lowing is a specification.

, UNITED smrns PATENT curios.

EDWARD BENNETT, OF OLMSTED, U'ldlil.

mon'rmne-epsnsrnn.

Specification of hetters Intent.

resented Sept. 8, 1914.

, Application men August 2c, 1905, Serial Not 150,358 neutral-reFebruary rem. semim. 81?,055.

To all whom it may concern: Y

Be it known that L EDWARD Bhnnn'rr, a citizen of the United States,residing at Olmsted, in the county of Utah State of Utah, have-inventedor discovered certain new and useful Improvements in LightningArresters,' of which improvements the fol The invention herein describedrelates to certain improvements 1n lightning arresters used for thepurpose of protectm powercircuits and apparatus from the a normalpotentials resulting "either from lightning disturbances or from. theinherent .charslc teristics of the system under the disturbing influenceof switching 'operatiohs, short oir-' cliits, grounds, and o pbrtitionsor accidents or alike nature. p

.The invention hasfor its object the rapidand yet gradual suppression ofth'e'dynamic current flow whichv always results across in nrrester whenthe arrester functions in discharging an abnormal potential. The methodby which I accomplish this result. is to use in my arrester a spark gapwhich Will'be broken down at a potential a pre determined amount higherthan the normal Operating potential, the passage of the dis charge atthe abnormal potential across the arrester is accompanied by the dynamiccurrent arc and 1 cause the motion of this are along the spark gapelectrodes to auto matically and rapidly insert or include in thecircuit predetermined and fixed resistances of a rapidly increasingvalue, thus reducing the volume of the current to a point Where the arcis quietly suppressed.

The invention is hereinafter more fully described and claimed.

In the accompanying drawings, forming a part of this specification,Figure (1) illustrates diagrammatically the essential feat tures of What1 term my arrcstcr unit; Figs. (2), (2):and (2) illustrate the detailsof one form of arrester unit in which an air blast is used to cause thearc to travel along the electrodes more rapidly, and the insertedresistances consist of sections of a water column: Fig. (3) illustratesanother form of the arrester unit in which a magoetic field is used tocause the arc to'inove more rapidly along the electrodes, and the Imounted, preihsrabl in a verticslflposition en insulators (2);mountediadjaceut to this conductor are e number of conductors (3), whichare contiectedt'o pcints olon" a suit able res1stunce(d) one end of Whicl is con, inected to ground. The conductors (1) and are. 'preterablymounted inside it shaft 5 of wood or other'meteriahpreferably inonconductingr (10) represents a power station containing transformers(11), "and generating apparatus (12),;which it is delsired to protect,"(:13)! represents the trans mission vires'leacing from the station.

In the ructice of my'invention, the conductor (1) is connected to one ofthe power wvires (l3) and the distances between the conductors (1)andKB) are so proportioned that the lowest gap (6) which is the shortestwill break down at a certain predetermined lpotential. \Vhen this gapbreaks down; the

dynamo current follows and the are so es :tablished rises along theelectrodes due to lthe heating of the air: in rising, one end of the arctravels up the conductor (1) endthe other end jumps up from conductor(3) :toconductor (3) immediately above it and iso on, each time insertidetermined amount of t 1e resistance (4) m ;the path of the current andthereby decrees" ting the current. In order to suppress the are morerap- ;idly, I prefer to supplement this natural !draft which causes thearc to jump up from conductor to conductor by a blast up the shaftproduced by any suitable means such an aspirator at the bottom of theshaiit fed by a smalljet of compressed air or by Qa fan motor (7) *or bythe action offmagnetic. field as illustrated in Fig.

Fig. 2 illustrates the details of an arrester Iunit as constructed forservice on a 40,000 -volt,, three phase transmission system. Theconductor (1), mouuted on insulators (2), is connected to one of theWires of the transmission line. The conductors (3) which are formed ofiron or copper Wire project into a Water column (4) which; constitutesthe an additional pr e-y 3 of the path from (8) to conductor (3)passzthe lower gap (6) is adjusted so that its breaking down potentialwill be higher than that of the upper gap (8) and the cross section andlength of the water column has been so proportioned that the resistancein the columnfrom the gap (6) to ground is low, (in this particular unit280 ohms) and the resistance from gap (8) to ground is much higher (2500ohms). With the gap (8) adjusted so that it will break down at apotential above the normal operating potential and the gap (6) set sothat it will break down at a potential 7 0% above thenormal operatingpotential, it the potential of the line wire, due to any cause, rises toa point 50% above the normal operfating potential, the gap (8) willbreak down and a path to ground is provided through the water column.

If the accumulated charge or disturbance is relatively light so that theconductivity ground is sufficient to prevent any further rise ofpotential, the gap (6) will not break down and the dynamic current whichcan flow will be greatly limited by the relativel high resistance in thedischarge path. -I however, the conductivity of the path provided by thebreak down of gap (8) is not sufficient to prevent a further rise ofpotential, the potential will continue to rise until it becomes high,enough to cause gap (6) to break down ,when'a further rise will befprevented by thevery high conductivity 0 the path to ground soprovided. In either case, the are so established isdriven up the-shaftso rapidly that it is difficult to follow it with the eve, the wholeoperation from the passage oif the discharge across the gap (6) to thetime when the are has reached the topmost (from which-point theresistance of the water column is 11,000 ohms) consuming about one tenthof a second. Moreover the are, in traveling up the conductor (1) and injumping up the conductor (3), does not draw out in length and becomethirty or forty feet long as in the ordinary horn arrester under similarconditions but remains quite short (about six inches in length) andsprings almost directly across from conductor (1) to the conductor (3)which is about opposite that end of the are which rests onconductor (1).

While I have given certain resistances and proportions, I do not limitmyself to these proportions. They have been mentioned forv the purposeof illustrating the principle of my invention and it-must be clearlyunderstood that these proportions areentirely unsuited except for aparticular power system ahd set of conditions.

In Fig. 3; 1, 2, 3, 4, 6 and 14: designate the same elements as in thefigures previously described. The resistance column (4) is composed ofcement and graphite suitably proportioned to obtain the desired steps inthe resistances between the projecting conductors (3) which may consistof expanded -metal which has been embedded in the column during itsconstruction. In this case the conductors (3) may be dispensed withentirely and one terminal of the arc may be caused to travel directly upthe face of the cement-graphite resistance column. I prefer to make thecross section of the column at the base much greater than at the top toprovide a greater thermal capacity for the greater amount of energywhich is expended in the base and thus preclude any objectionable risein the temperature of the column when the arrestcr discharges the line anumber of times in rapid succession. To cause the arc to rise rapidly, Icombine with this arrester the choke coil which is generally used in the8 line wires at power stations to reflect incoming surges of potential,and so locate the choke coil (9) with reference to the electrodes (1)and (3) that the magnetic field from the choke coil causes the arc totravel rapidly upward.

While I have mentioned and specifically described certain forms ofresistances and certain supplementary means of giving to the are a rapidmotion, I do not limit myself to the use of these forms or means; theuse of other forms of resistance such as metallic resistances and ofother means of imparting to the are a rapid motion comes within thescope of my invention.

The action of my arrester is entirely different from that of the wellknown horn gap. In the horn gap arrester it is true that the current isdiminished somewhat when the arc draws out to a great length but theresistance even of a ten or twenty foot air path is slight and is veryuncertaip. Indeed after the arc has drawn out to a great length thecurrent is still so high that the instantaneous extinction whichsometimes occurs under these conditions gives rise to disturbances ofgreater severity than that which initially caused the horn gap to breakdown. On the other hand, in my arrester I do not attempt to draw out theare but I cause the motion of the arc and more particularly of the twoterminals of the arc to insert or include in the circuit predeterminedand fixed resistances and I proportion these resistances so that thecurrent is cut down by gradual steps to a point where the extinction ofthe arc produces no more efiect on the system than the throwing ofi of amotor load.

I claim as my invention:

'1. A lightning arrester including in combination, spaced electrodesforming a spark gap, one of said electrodes including conductors locatedat a plurality of spaced intervals along said electrodes and suitableregap, one of said electrodes includin sistanee connecting saidconductors, whereby the travel ofthe arc along the electrodes inzerts intheucg gcuit' an increasin resistance.

A g figgfjlarrester 'inclu ing in combination, spa electrodes forming aspark projeetin conductors located at a plum ity of 5 seed intervals.throughout the entire length .of the ele'ctrodemand suitable resistanceconnecting said conductors whereby the travel of the are along theelectrodes inmrts in the circuit an increasin resistance.

3. A lightnin arrester inclu in combination, space electrodes one ofwhich is connected with a transmission line, and the other of which isconnected with the ground,

. said electrode connected with the ground ining being 0 whereby;

member.

eluding projecting conductors located at a plurality of spacedthroughout the length of the; electrode, a casing surrounding saidelectrode, said casn at the top and bottom, a fan located at t e bottomof the casing for causing a circulation ofair through the casing, theare is caused to travel ra i y along t e electrodes. f

4. A lightnin arrester comprising relativel long an short divergingterminal mom rs, a resistance conn of overlapping conductors that areconnected at intervals to the resistance and constitute an extension ofthe shorter terminal 5. A lightning arr-ester comprising relaintervalsextending plurality of to the shorter terminal member, and a pluralitytivel long and short diverging terminal mem rs, a resistance connectedto the shorter termmal member a plurality of over-lapping conductors tat are connected 'ance support for said over-lapping con ductcrs.

7. A lightning arrester comprising terminal "members one of whichconsists of a single high-resistance support for said conductors. I

8. A lightning arrester comprising a pair 10f terminal members one ofwhich consists of a refractory high-resistance member and a series ofover-lapping conducting members su ported thereby.

n testimony whereof I have hereunto subscribed my name this 29th day ofMay, 1908.

EDWARD BENNETT.

Witnesses:

H. G. Nien'rmoans, E. A. Tnonmmm.

over-lapping conductors and a

